My brother told me that he was going to do everything possible to take me out of the will. My dad is still alive but the will was set up in a revolcable trust 15 to 20 years ago and I am on it.

Only your dad can change a will. With it being revocable then it can be changed while he is alive. Your brother has no legal standing to change things for your father.

Children who are around an aging parent all the time manage to get them to change wills and trusts every day. Your father may hold to it the way he wrote it or he may not - there's no way we can predict.

Is your brother a greedy grubby guy or are you a deadbeat son? You don't have to answer that - this is a law forum, not family relationships. Just beware.

Only the dad can change it, the other person can try and talk the dad into changing it.

An executor has no power over the estate until the testator dies. Once the testator dies, the executor is then responsible for processign the estate according to the terms of the will. So he can't change the will at all. Also, a trust tends to be outside the estate and not part of the will. If the trust was already setup, it should have already been funded though it could be funded as part of the will. Is your brother also trustee of the trust?

However, your brother can try to influence your father to change the will and/or the trust while your father is still alive. If you father trusted him enough to appoint him executor, he may be able to influence your father. Also once the executor takes over the estate, there are things he can do to affect how the estate is distributed. But he still has a fiduciary responsibility to process the estate according to the will.

Is the father mentally competent? If not, not even he can change it.